As described for example in Stevens U.S. Pat. Nos. 4,000,739, 4,421,296 and elsewhere, catheter sheath introducers are disclosed for the purpose of providing access by catheters to the arteries of a patient for purposes such as percutaneous translumenal coronary angioplasty (PTCA) and other surgical procedures. The catheter sheath introducer defines a housing from which extends a flexible tube portion having a length on the order of six inches, which tube portion is surgically emplaced into the artery of a patient. Then, catheters may be inserted and withdrawn through the tube portion for access, often by several different catheters in succession, to the arterial system of the patient without creating undue abrasion injury at the access site.
Also, the housing of the catheter sheath introducer is tubular, with a proximal portion thereof being obstructed by an elastomeric barrier which defines a slit. This elastomeric barrier serves as a hemostasis valve to limit or prevent the backflow of blood from the artery out of the proximal end of the catheter sheath introducer, while at the same time permitting catheters to be advanced through the introducer. One of numerous examples of such a slit elastomeric barrier for use in a catheter sheath introducer is disclosed in the cited Hillstead U.S. Pat. Nos. 4,895,565 and 4,798,594.
In PTCA and other surgical procedures, the surgeon may use varying sizes and types of catheters in the same procedure. Finding one catheter to be unsuccessful in performing the desired procedure, the surgeon may withdraw it through the catheter sheath introducer and replace it with another catheter. Also, there is a wide variety of catheters which may be used to enter the arteriovenous system of the patient, some of which catheters are more desirably used with certain types of catheter sheath introducers, and other catheters being more desirably used with other types of such introducers. Catheter sheath introducers may vary as to the type of elastomeric barrier valves used, the stiffness, diameter, and length of the sheath tube carried by the introducer, and the like. Thus, a well equipped hospital or clinic will have to stock a substantial number of different of catheter sheath introducers, which represents both a complexity in the control of inventory, and a tie-up of capital.
In accordance with this invention, a modular catheter sheath introducer is provided which may be modified in accordance with the immediate needs of the surgeon prior to the surgical procedure in a manner which depends upon the nature of the catheters expected to be inserted through the introducer. Thus, an improved flexibility of selection of a particularly desired catheter sheath introducer is provided, with a reduction in the amount of inventory stored by the hospital or clinic, to provided a maximum degree of flexibility of use to the surgeon at a minimum of inventory cost and administration.